Combustion - Continued.

Here are some key points to remember:

a. Many heavy fuel oils are not easy to burn in their native state. Heavy oils (such as Bunker C, also referred to as #6 Oil) must be vaporized before combustion can take place.

b. Combustion of liquid fuels is actually a two-phase process. In the first phase, fuel is vaporized. In the second phase, proper conditions are created so that combustion can take place.

The above should explain the fact that we need heat before combustion can take place for the liquid fuels. The purpose of a matchstick (or an ignitor) is to provide the initial heat – to convert some of the fuel into gaseous form.